Elevator



(No Model.)

0. W. BALDWIN. ELEVATOR.

Patented Apr.24,1883.

UNITED ST TES PATENT GFFICE.

oYnUs W. BALDWIN, or oHIoAco, ILLINOIS.

ELEVATOR.

SPECIFICATION forming part of Letters Patent No. 276,332, dated April 24, 1883.

' Application filed February' 4, 1882. (No model.)

To all whom it may concern:

rectly into the cylinder of an elevator.

Be'it known that LCYRus W. BALDWIN, of Chicago, Cook county,,State of Illinois, have invented certain Improvements in Elevators,

of which the following. is a specification.

Myinveution relates to that class of elevators in which the pressure of water upon a pie ton actuates the latter to raise the cage, and has for its object to dispense with the usual elevatedtanl: or water-reservoir and pump the water directly into the cylinder. My inventionincludes other improvements hereinafter described. I

My invention consists in means whereby to avoid the shocksand straining of'the supports. liable to result when the water is pumped di- 1 I have found that byiuterposing an airland water chamber between the pump and the piston the pulsations ofthe pump are absorbed and the irregular motion of the cage prevented. ,This arrangement may be embodied in apparatus of various forms. One which I have found to be most effective is illustrated in the acccompanying drawing, in which the figure represents in elevation a Baldwin hydraulic elevator with my improvements applied thereto. A is the cylinder, containing the usual piston connected tothe piston-rod a, and operating upon thecage. B is the valve-case, bthe discharge-pipe," and d e the circulating-pipes connecting the case with the opposite ends of the cylinder. The construction ofthese parts is so well known that further 'idescription of the same is unnecessary. The pumpD is of any suitable character,

1 and communicates with the cylinder; or it may communicate with the valve-casing B or with the pipe '41 in such manner that water may be pumped into. the cylinder to move the piston and raise the cage. 7

With the water-passage, at some point between the pump and the piston, communicates a vessel or case, E, which, as shown, is closed at the top and filled or partly filled with air, which will be compressed when the pressure on the water increases from the increasedaction of the pump, and by thus yieldingabsorbs the pulsations that would otherwise be transmitted to the cage. I have found that by into the cylinder without interfering with the steady, uniform motion of the cage.

When the valve in the case B is shifted to flower the cage the water circulates from one side of the piston totbe other through the pipes d c. In the ordinary Baldwin elevator {(where the pipe (I communicates with a supplytank) this is practicable, the tank supplying the additional water needed on the lowerside jot the piston and taking up the surplus when the piston descends; but it will be seen that it the communication with the supply is cut joff during circulation, as will be the case where a pump is used, there would not be feuough water from the space above the piston Y (contracted by the piston-rods) to (ill the space 2 below, and there would consequently be avacuium formed belowthe piston, causing the car Ito jump, from the contraction of the air when the valve is opened.

The use of the case E prevents this, as by the expansion and contraction of air therein the extra supply of water may be drawn from or forced intothe pipes, which could notresult if all the chan- {uels were full of water.

E may be arranged at the upper end of the pipe (I, or may communicate with the upper end of the cylinder.

It will be obvious that the case E need not be closed at the top when it is at. such a height that the action of the pump will not expel the water therefrom.

It must be apparent'that as the action of the pump starts the apparatus the pump should 1 This may be I the cylinder communicates a vessel, G, open pump into operation, which continues until the closing of the discharge. by the shifting of the valve in the case B increases the pressure in the vessel G and causes the steam-valve to be closed.

The shifting of the main valve from the cage thus both opens and closes the ports and starts and stops the pump. various devices may be used to effect this result.

A cook, a, in the communication between the vessel G and the pipe (1 serves to regulate the action of the appliances controlling the steam-valve.

It has been common in hydraulic elevators to discharge the water from the cylinder into an open tank, and to pump it thence to a tank at the top of the building. In place of the open tank, I prefer to use a closed tank, K, communicating with the dischargepipe'b and with the suction-pipe h, leading to the pump. Asthe pump exhausts the tank the rarefaction of the air or partial vacuum produced therein greatly facilitates the discharge of the water from the lower end of the cylinder and enables me to increase the speed of the cage.

A spring-loaded inlet or vacuum valve, m, prevents danger from too great a vacuum, and a weighted or spring-loaded relief-valve, 8, prevents an excess of pressure within the tank, appliances being used whereby the pressure on each valve may be regulated. V

It will be apparent that the vacuum-tank may be employed with hydraulic elevators of various constructions.

It will be obvious that or case arranged at or near the upper end of the cylinder and communicating with the water between the pump and piston, substantially as set forth.

3. The combination of the elevator-cylinder and its piston, inlet and discharge pipes, the pump and pipe leading therefrom to the inlet-pipe ot' the cylinder, and'pump startingvalve, and cable or its'equivalent, whereby the said valve is operated from the cage.

4. The combination, with the cylinder, pu mp, and starting-valve ot' the pump, of a case having a piston constructed to be operated by the pressure in the supply-pipes, and connected to the startingvalve to govern the latter, substantially as set forth.

5. In a hydraulic elevator where the piston is operated directly from the pump, the combination of the steam-pipe, the starting-valve, the pump, the pipe leading therefrom to the cylinder, the vessel attached to said pipe and communicating with the Water therein, and having a piston with rod connecting with said starting-valve, substantially as shown and described.

6. The combination of the cylinder, pump, pipes, valve f, steam-pipe, vessel G, containing a piston connected to the valve, and cook a, substantially as specified.

7. In a hydraulic elevator where the piston is operated by water under pressure, elevated by a pump, the combination, with the discharge-pipe ot' the cylinder and the pump, of the closed tank having communication with such discharge-pipe and with the pump by means of its suction-pipe, substantially as shown and described.

8. In a hydraulic elevator where the piston is operated by water under pressure, the combination,with thedischarge-pipeofthecylinder, and the pump, of the closed tank having conr munication with such discharge-pipe and with the pump by means of its suction-pipe, said tank having the relief-valves and vacuumvalves, substantially as set forth.

9. The combination of the cylinder A, pipes d and 6, closed tank K, and pump communicating with the tank by means of the suctionpipe, and with the cylinder by means of a pipe, d, substantially as set forth.

In testimony whereofI have signed my name to this specification in the presence of two subscribing witnesses.

HOLMES Hoes HENRY L. KENT. 

